1 . Field of the Invention
The present invention relates generally to the fabrication of magnetic heads for hard disk drives, and more particularly to the fabrication of a narrow P2 pole tip and a fine pitch induction coil using a single image transfer step.
2 . Description of the Prior Art
Efforts to increase the performance characteristics of hard disk drives have focused on increasing the areal data storage density of the magnetic hard disks and increasing the data writing rate of magnetic heads in writing data to the hard disks. As will be understood from reading this detailed description, the present invention advantageously affects both of these hard disk performance characteristics.
One way to increase the areal data storage density is to decrease the width of the data tracks upon the hard disk media. Narrower data tracks allow for more tracks per inch (TPI) to be written on a disk, thereby increasing the areal data storage density of the disk. The well recognized method for decreasing the width of the data tracks is to decrease the width of the P2 pole tip of the magnetic head, because the width of the P2 pole tip generally determines the width of the data track that is written by the magnetic head. Prior art photolithographic techniques for fabricating P2 pole tips are currently reaching the limits of process accuracy, in that it is difficult to accurately and reliably fabricate high aspect ratio P2 pole tip trenches utilizing photolithographic techniques. Recently, high aspect ratio P2 pole tip trenches have been fabricated utilizing reactive ion etch (RIE) techniques, which have produced good results where the P2 pole tip is subsequently electroplated into the RIE created trench. The present invention is an improvement in the RIE P2 pole tip fabrication process for the fabrication of magnetic heads, as is discussed in detail below.
To improve the magnetic head data writing rate, prior art magnetic heads have been fabricated with higher aspect ratio induction coils. Such high aspect ratio induction coils allow for the individual induction coil turns to be spaced closer together, creating a fine pitch induction coil. Where a fine pitch induction coil is fabricated, the P2 pole yoke can be shortened, thus creating a similarly shortened magnetic flux circuit through the P1 and P2 poles, such that the data writing rate of the magnetic head is increased.
The present invention advantageously utilizes one dielectric layer, one RIE mask and image transfer step, and one RIE step to create both a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil. In so doing, fabrication problems associated with separate RIE processes for creating a P2 pole tip and for creating a fine pitch induction coil are avoided, and the fabrication of an improved magnetic head is simplified.